Identify the correct option based on the following reaction sequence:
Acetic anhydride $\xrightarrow[(ii) EtOH/H^+/\Delta]{(i) H_3O^+} (A)$ $\xrightarrow[(ii) H_3O^+/\Delta]{(i) NaOEt} (B)$

Which of the following reactions give $RCONH_2$?

The product $(X)$ of the reaction is:

Calculate the value of $x + \text{molecular mass of } (C)$,where $x$ is the number of moles of $PhMgBr$ consumed in reaction $(a)$ and $(C)$ is the gas evolved in reaction $(b)$.
$(a)$ $3\text{-hydroxy-5-formylbenzoyl chloride} + x \ PhMgBr \xrightarrow{\text{excess}} (A)$
$(b)$ $2,5\text{-dioxocyclohexanecarboxylic acid} \xrightarrow{\Delta} (B) + (C) \uparrow$

Give simple chemical tests to distinguish between the following pairs of compounds.
$(i)$ Propanal and Propanone
$(ii)$ Acetophenone and Benzophenone
$(iii)$ Phenol and Benzoic acid
$(iv)$ Benzoic acid and Ethyl benzoate
$(v)$ Pentan$-2-$one and Pentan$-3-$one
$(vi)$ Benzaldehyde and Acetophenone
$(vii)$ Ethanal and Propanal

Compound $A$ was treated with a large excess of $CH_3MgBr$. The resulting product was exposed to $POCl_3$ /pyridine to give compound $B$,as one of many products.
Which of the following compounds can be $A$ ?